Fluid pressure device



June 6, 1961 J. L. MURRAY FLUID PRESSURE DEVICE 3 Sheets-Sheet 1 Filed July 29, 1955 INVENTOIR June 6, 1961 MURRAY 2,987,004

FLUID PRESSURE DEVICE Filed July 29, 1955 3 Sheets-Sheet 2 a INVENTOR j]? W i 6 Jawoms L .Mmxnr & I 0

ATTORNEYS Jun 6, 1961 J. L. MURRAY 2,987,004

FLUID PRESSURE DEVICE Filed July 29, 1955 3 Sheets-Sheet 3 INVENTOR ATTORNEY5 United St e Pat ,9.

2,987,004 FLUID PRESSURE DEVICE Jerome L. Murray, 445 E. 58th St., New York, NY; Filed July 29, 1955, Ser. No. 525,296 17 Claims. (Cl. 103-149) The present invention relates to flexible tube fluid pressure devices, and more particularly is directed to improvements in devices of the kind having a resilient tube section and presser means movable along the tube section to locally flatten or reduce the cross-sectional area of the latter, so that the device can be employed either as a fluid pump, when the presser means is driven, or as a motor for driving the presser means, when fluid is pumped through the tube section.

Although flexible tube fluid pressure devices of the described character have been proposed long prior to the present invention, and many variations and modifications based upon the same general principles have been suggested, the only practical use of such devices has been as pumps of relatively low capacity and pressure in laboratories and the like, where the peculiar characteristics of this type of pump have been required and necessitated their use in spite of the recognized disadvantages and defects of the existing arrangements. Specifically, in existing fluid pumps of the described character, particularly pumps designed to have high rates of discharge at relatively high pressures, the repeated flexing of the resilient tube section causes cracking or other fatigue failure of the material of which the latter is formed after only a relatively short period of operation, so that frequent replacement of the tube section is required and, in fact, certain of the alleged advances in this art have been concerned, at least in part, with facilitating replacement of the tube section in view of the acknowledged frequent failures thereof. Further, in the existing flexible tube fluid pressure devices, the resilience of the tube section represents the only means therein for returning the tube section to its original cross-sectional area following the flattening thereof by the presser means. It is apparent that the efliciency of a device of the described character, when used either as a pump or as a motor, depends upon the difference between the normal cross-sectional area and the flattened cross-sectional area, the speed with which the tube section returns to its normal cross-sectional area following the flattening thereof, and the power that must be expended in effecting the local flattening of the tube section. If the resilience of the tube section is relied upon for the return thereof to its normal cross-sectional area, rapid return or restoration of the normal area can be achieved only with a relatively stifi tube section which results in greater power losses due to the strong resistance to flattening and also in increased susceptibility to fatigue failure of the tube section. If the tube section is designed for ease in flattening and for complete closing of the interior space in the flattened condition, then the resilient return of the tube section to its normal cross-sectional area is sluggish and may be incomplete to defeat any gain achieved by such complete closing of the tube section.

Accordingly, it is an object of the present invention to provide flexible tube fluid pressure devices, useful either as pumps or motors, and which are capable of maintenance-free operation with an efliciency unattainable by existing devices of the described character.

A specific object of the invention is to provide a flexible tube fluid pressure device wherein the tube section, which is repeatedly flattened and then restored to its original or normal cross-sectional shape, is constructed to resist fatigue or other failure thereof so that the device can be continuously operated for long periods without requiring replacement of the tube section.

In accordance with the present invention, the high resistance of the tube section to fatigue or other failure is achieved by forming the tube section of natural or synthetic rubber or other suitable flexible and resilient material having at least one layer of textile fabric, cord or the like, embedded therein.

, Another specific object of the invention is to provide a flexible tube pump of the described character and having provision for mechanically resorting the tube section to its normal cross-section shape following the flattening thereof so that rapid return of the tube section to its normal shape can be achieved with a tube section designed to be easily flattened and to avoid fatigue failures.

Still another object is to provide a flexible tube fluid pressure device of the described character, useful as a pump or as a motor, and wherein the pressure means for locally flattening the tube section is in the form of at least one roller having a central peripheral groove into which the flattened portion of the tube section can deflect to partially open the cross-section of the flattened tube section in response to an excess pressure within the latter so that the pump or motor is thereby given a safety pressure relief feature.

A further object is to provide a flexible tube fluid pressure device of the described character which acts as a multi-stage pump.

A still further object is to provide a flexible tube fluid pressure device of the described character capable of simultaneously pumping two or more different fluids.

It is still another object of this invention to provide a flexible tube fluid pressure device of the described character capable of operation as an oscillating motor, for example, for driving the windshield wipers of automotive and other vehicles.

The above, and other objects, features and advantages of this invention will be apparent in the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings forming a part hereof, and wherein:

FIG. 1 is an elevational view of a flexible tube fluid pressure device embodying the present invention, but with the housing thereof being broken away and in section to expose the operating parts of the device;

FIG. 2 is a vertical sectional View taken along the line 2-2 of FIG. 1; ,7 FIG. 3 is a fragmentary, perspective view, on an enlarged scale, of a section of tube for use in flexible tube fluid pressure devices in accordance with the present invention;

FIG. 4 is a fragmentary, elevational view of a flexible tube fluid pressure device constructed in accordance with still another embodiment of this invention;

FIG. 5 is a transverse sectional view taken along the line 55 of FIG. 4;

FIG. 6 is an elevational view of a multi-stage flexible tube fluid pressure device embodying the present invention, with the housing of the device being broken away and in section to expose the operating parts of the device which are viewed in a direction normal to the axis of rotation of the presser means included in the device;

'FIG. 7 is a view similar to that of FIG. 6, but showing still another embodiment of the invention that is capable of simultaneously pumping two different fluids;

FIG. 8 is a fragmentary, end elevational view of the device in FIG. 6, as viewed in the direction of the arrows 8-8 on the latter;

FIG. 9 is a view similar to that of FIG. 1, but showing still another form that the invention may take to provide a pump capable of simultaneously pumping two different fluids;

' FIG. is an enlarged perspective view of a section of two concentric tubes employed in the device of FIG; 9;-

FIG. 11 is a fragmentary, sectional view illustrating theconstruction of a flexible tube fluid pressure device embodying a pressure relief feature in accordance with the present invention, and shown conditioned for operation under normal pressures;

FIG. 12 is a view similar to FIG. 11, but showing the condition of the device when excess pressures are encountered;

FIG. 13 is an elevational view of a roller and the associated flexible tube, shown in cross-section, that may replace the rollers of the device of FIG. 6 in accordance with a further modification embodying this invention;

FIG. 14 is an elevational view of an oscillating motor embodying the present invention;

FIG. 15 is a fragmentary sectional view of a preferred form of tube; and

FIG. 16 is a fragmentary sectional view of another form of tube.

Referring to the drawings in detail, and initially to FIGS. 1 and 2 thereof which illustrate a device embodying the present invention and generally identified by the reference numeral 10, it will be seen that the device 10 includes a rigid casing 11 defining a surface 12 which, in the device 10, is arcuate, a flexible tube 13 lying against the surface 12 and having one of its ends connected to a source or supply (not shown) of fluid, and an assembly, generally identified by the reference numeral 14, operative to locally flatten the tube 13 against the surface 12, while the location of such flattening of the tube 13 is made to travel along the latter, either by driving the assembly 14, as in the case of pump, or by supplying a fluid under pressure to the tube 13, as in the case of a motor, for driving the assembly 14. Preferably, the tube is molded in the form seen in FIG. 1 with connecting piece 13A.

The assembly 14 includes a support 15, in the form of a disc, mounted rotatably on an axle 16 which is journalled in a hollow boss 17 on the casing 11 concentric with the arcuate surface 12 of the latter. The support disc 15 rotatably carries two rollers 18 at diametrically opposed locations and with the axes of the rollers 18 extending parallel to the axis of rotation of the disc. The rollers 18 are radially disposed so that the radial distance from their peripheries to the surface 12 is less than the normal outside diameter of the tube 13, whereby the rollers 18 act to locally flatten the tube 13 against the surface 12, as clearly shown in FIG. 1.

If the shaft or axle 16 is rotated, for example, by connection to an electric, or other motor (not shown), to cause rotation of the disc 15 and rollers 18 in the direction of the arrow 19 (FIG. 1), while the end 20 of tube '13 is connected to a supply of fluid, it is apparent that the flattening action of the rollers 18 will travel along the tube 13 from the inlet end 20 of the latter toward the opposite or discharge end of the tube. Since the traveling Q by the rollers 18, and the extent to which such return to the original shape is effected before flattening again occurs, since these factors largely control the change in cross-sectional area of the tube 13 resulting from the passage of the rollers 18 along the latter.

In accordance with one aspect of the present invention, the assembly 14 includes means for positively and rapidly restoring the tube 13 to its original shape following the flattening thereof by the rollers 18. In the device 10, such means consists of rollers 21 rotatably mounted on the support disc 15 at locations immediately following the rollers 18, considered in the direction of movement of the latter, so that, after a roller 18 flattens a portion of the tube 13, the related roller 21 acts upon that portion of the tube to restore it to the original or normal cross-sectional shape. As seen in FIG. 2, each roller 21 has two axially spaced apart, peripheral flanges 22, with the distance between the latter being substantially equal to the normal external diameter of the tube 13. Thus, the roller 18 exerts a pressure radially outward against the tube 13 to flatten the latter, and such flattening causes an increase in the lateral dimension of the tube at the flattened zone beyond the normal outer diameter of the tube, while the following roller 21 laterally squeezes the flattened zone of the tube between its flanges 22 and thereby restores the tube to its normal circular cross section.

Since the tube 13 is positively restored to its normal cross-sectional shape following the flattening thereof, a tube of relatively low resilience can be employed, as compared with the existing devices of the described character where the resilience of the tube alone is relied upon to effect its return to normal shape, and this low resilience decreases the resistance to flattening by the rollers 18, so that the efliciency of the device is improved, and also decreases the susceptibility of the tube to fatigue failure.

Although a particular arrangement of the rollers 21 has been illustrated for applying shape restoring forces to the tube 13 in the directions at right angles to the flattening of the latter, it is apparent that other structural arrangements for applying the shape restoring forces may be easily devised. For example, the surface 12 of casing 11 may be bounded, at one side, by an annular surface (not shown) in a radial plane, while the shape restoring rollers have a radial flange only at the side thereof remote from the above mentioned annular surface so that the flattened zone of the tube is then laterally squeezed between the single flange of the restoring roller and the related annular surface of the casing.

flattening action of the rollers 18 will produce relatively high pressures, in front of the flattened zones, and relatively low pressures, in back of the flattened zones, a pumping effect is created within the tube from the inlet end 20 toward the opposite or discharge end of the tube.

It is to be noted that the device will act as a positive measuring pump.

If the device 10 is to be employed as a motor, the end 20 of the tube 13 may be connected to a source (not shown) of fluid under pressure, for example, to the discharge of a fluid pump, so that the fluid pressure acts I in back of the flattened zones of the tube and urges such zones along the latter toward the discharge end of the tube thereby causing rotation of the assembly 14.

Among the factors determining the efficiency of the device 10, particularly when it is employed as a pump, are the rapidity with which the tube 13 returns to its original cross sectional shape after having been flattened Further, in accordance with the present invention, the device 10 of FIGS. 1 and 2, as well as any and all of the other embodiments of the invention hereinafter described in detail, preferably have a flexible tube construction of the kind illustrated in FIG. 3, the tube 13 of FIG. 3 having a fabric layer 23 of suitably flexible and heat resistant yarn embedded in the body thereof between inner and outer layers 24 and 25, respectively, which may be formed of natural or synthetic rubber or of any other suitably flexible, resilient and fluid impervious material. The fabric layer 23 takes much of the stress imposed on the tube 13 during the repeated flattening of the latter and further permits the designing of the tube to facilitate the complete closing of the latter when it is flattened and to prevent the cracking, or other fatigue failure, of the tube at the locations where it is sharply bent in being flattened. Thus, as seen in FIG. 3, the wall of tube 13 has relatively thin portions 26 at diametrically opposed locations, while the tube wall is gradually thickened radially inward at the opposite sides of the thin portions 26, as at 27, so that, when the tube 13 is flattened in the direction normal to the diametrical plane passing through the thin wall portions 26, the tube can fold at the thin wall portions 26 with the thickened wall portions 27, at opposite sides of the latter, riding against each other to permit complete closing of the interior of the tube without excessively stressing the tube wall, particularly where the latter is folded.

A preferred form of tube is seen in FIG. 15 wherein fabric layer 45 is embedded therein in a manner similar to that seen in FIG. 3. The tube has a thickened portion 46 adjacent surface 47 of the casing, this being arranged to be less than the width of the tube when in compressed condition. The edges 47 are directed toward the casing. The roller 48 does not have to be shortened in this form.

Another form of tube is seen in FIG. 16 where annulus 49 is laid on surface 59 of the casing, the width of the annulus being such as to permit the edges 51 of the tube 52 to bend over. Roller 55 is similar to the rollers described for other forms. A rib 54 can be joined on tube 52, said rib being engageable in slot 55 in back-up strip 49. Tube 52 may have fabric 56 imbedded therein similar to the other described tubes. There is suflicient clearance in slot 55 so that upon over pressure, the rib 54 and related parts of the circular part of the tube can move downwardly and relieve pressure.

Although the opposite ends of the tube 13 enter and leave the casing 11 in the same general direction in the device it) of FIGS. 1 and 2, it is also proposed, in accordance with the present invention, to provide a flexible tube fluid pressure device, wherein the flexible tube makes a complete helical turn within the casing and enters and leaves the latter tangentially in opposite directions. An arrangement of this kind is illustrated in FIG. 6, where it will be seen that the device a includes a casing 11a defining a generally cylindrical internal surface 12a against which a full helical turn of the flexible tube 13a is disposed. The inlet end 20:: of tube 13a and the opposite end of the latter extend tangentially from the casing 11a in opposite directions, and a disc a rotatable within the casing 11a about an axis concentric with the surface 12a carries rollers 18a for flattening the tube 13a against the surface 12a.

Although the above described embodiments of the invention flatten the flexible tube against a surface that is arcuate in the direction of movement of the flattening rollers, it is to be noted that devices embodying the present invention may have the flexible tube flattened against a straight surface or a surface having straight portions interconnected by suitable curved portions to form a continuous surface.

Referring to FIGS. 4 and 5, it will be seen that the device 10b, there illustrated, includes a straight, channel shaped member 11b defining a straight surface 12b (FIG. 5) against which the tube 13b rests, while the assembly 14b, for locally flattening the tube 13b against the surface 12b, includes a carriage 15b having a tube flattening roller 18b rotatably mounted thereon to engage the tube 13b and a pair of stabilizing rollers 17 b rolling against the underside of the member 11b to react against the latter with a force equal and opposite to the force on the channel member resulting from the flattening of the tube by the roller 18b.

If the entire member lib is straight, as shown in FIG. 4, it is apparent that the assembly will be reciprocated longitudinally along the member 11b either by suitable mechanical means (not shown), when the device 10b is to be used as a reciprocating pump, or by the supplying of fluid under pressure alternately to the opposite ends of the tube 13b, when the device 10b is to be employed as a reciprocating motor. However, it is apparent that the channel member 11b may merely form a straight run or part of a closed path, the other parts of which are not shown in the drawing, and that, in that case, the assembly 14b may form a link in a continuous drive chain (not shown) so that the flattening action of the roller 18b then moves along the tube 13b in only one direction.

In any case, it will be noted that the flattening roller 18b preferably has an axial length which is smaller than the lateral dimension of the tube 13b when the latter is flattened (FIG. 5) so that the folded portions of the tube are not contacted and bulge away from the surface 12b,

and this arrangement is particularly necessary, when the tube has the construction described above in connection with FIG. 3 of the drawings, in order to accommodate the thickened wall portions 27 of the tube. With a tube construction of the kind shown in FIG. 3, the thickened Wall portions 27 ensure complete closing of the interior of the flattened tube, even when the flattening roller does not contact the folded portions of the tube, and thereby avoids the sharp bending of the tube at the folded edges and the corresponding tendency to cause cracks in the tube at the folds thereof.

Referring now to FIGS. 6 and 8 of the drawings, a device embodying the present invention and capable of operation as a multi-stage pump is there illustrated and generally identified by the reference numeral 100.

The device 10a includes a casing 11a defining a cylindrical surface 12a against which a plurality of helical turns of a flexible tube 13a are disposed. An assembly 14a for simultaneously flattening all of the turns of the tube 13a against the surface 12a includes a support 15a, in the form of a disc, mounted on a rotated shaft 16a which is journalled in a hollow boss 17a on the casing 11a concentric with the surface 12a. Two flattening rollers 18a are rotatably mounted on the disc 15a at diametrically opposed locations with their axes extending parallel to the axis of rotation of disc 15a, and the rollers 18a are suificiently long to simultaneously engage all of the helical turns of the tube 13a within the casing 11a. Thus, if fluid is supplied to the tube 13a at the end 20a thereof and the assembly 14a is rotated in the direction of the arrow 19a (FIG. 8), the fluid within the helical turns of the tube is subjected to repeated pumping actions and discharged from the tube at the end thereof remote from the inlet end 20a.

Assuming that three helical turns of the tube 13a are provided within the casing 11a and that the disc 15a carries two flattening rollers 1811, as in the embodiment of FIGS. 6 and 8, it is apparent that, at any instant, the tube 13a will be flattened at six locations between its inlet and outlet ends. If this arrangement is compared with the arrangements in FIG. 1 where the single turn of the flexible tube is flattened at only two locations between the inlet and outlet ends of the tube, it will be apparent that the device of FIGS. 6 and 8 provides a multiple pumping action equivalent to that obtainable by connecting in series three of the devices of the kind illustrated in FIG. 1 or FIG. 4.

With the construction illustrated in FIGS. 6 and 8, it is apparent that the rollers 18a contact each flattened portion or zone of the tube 13a across the entire lateral width thereof contrary to the preferred situation described above in connection with FIG. 5, where the roller 18b is shorter than the lateral width at the flattened zone to relieve the folded edges of the flattened tube. In order to achieve the same advantageous effect in a multi-stage pump of the kind illustrated in FIGS. 6 and 8, each of the smooth, cylindrically surfaced rollers 18a of the latter may be replaced by a roller 18d, as illustrated in FIG. 13. The roller 1811 has a square thread 28 extending from the surface thereof, with the pitch of the thread 28 being substantially equal to that of the helical turns of the tube within the casing 110, and with the width of the outer surface or raised surface of the thread 28 being less than the width of the tube 13c at its flattened zones so that, as shown in FIG. 13, the thread 28 contacts each flattened zone of the flexible tube only over a substantial central portion of the zone and the folded edges are free of the actual flattening force. The rollers are driven through a ring gear 40 and gears 41 so as to remain in proper relationship with the tube.

Referring now to FIG. 7 of the drawings, a device We embodying the present invention is there illustrated and is generally similar to the device 10a of FIGS. 6 and 8, in that the casing lle and the flattening assembly 14a of the device 10a are substantially the same asthe casing 11a and assembly 14a of the device a. However, in the device 10c, turns of two tubes 13c and 13e are disposed within the casing 112 against the surface 12c of the latter and simultaneously flattened by the rollers 18c, so that two different fluids can be supplied to the inlet ends Me and 20s of the tubes He and 13a and simultaneously pumped from the other or discharge ends of the related tubes. Further, such can combine a pump and motor using one hose for fluids and the other hose for pressure, the latter operating the device as a motor.

FIGS. 9 and 10 show another arrangement for simultaneously pumping two different fluids in accordance with the present invention. The pumping device 10f of FIG.

.9 includes a casing 111 defining an arcuate surface 12 against which a tube assembly 13 is disposed. The tube assembly 13 (FIG. 11) includes an outer flexible tube 29 and an inner flexible tube 30 of substantially smaller diameter so that an annular space 31 is defined between the tubes 29 and 30. If desired, a connecting piece (not shown) of the same material can be located between inlet and outlet exterior parts of the hose adjacent assembly 14 The two different fluids to be pumped are supplied to the annular space 31 and to the tube 30, respectively, at the inlet end of the tube assembly 13 In order to pump the fluids through the tube assembly 13 the device 10 includes a tube flattening assembly 14 having a rotated support 15), in the form of a disc, and flattening rollers 18 which are rotatably mounted on the disc 15 at diametrically opposed locations and adapted to locally flatten the tubes 29 and 30 at zones progressing therealong, from the inlet end to the outlet end of the tube assembly, as the disc 151 is rotated.

FIGS. 11 and 12 of the drawings illustrate a modification of the flattening roller that may be substituted for the flattening rollers in any of the described embodiments of the invention in order to provide for release of excess fluid pressure. It will be seen that the roller 18g of FIGS. 11 and 12 has a centrally located, peripherally extending groove or recess 32 so that, during flattening of the tube 13g against the surface 12g of the casing 11g, the roller 18g normally contacts the tube only at surface areas of the roller adjacent the opposite ends of the latter, and the resilience of the tube 133 is suflicient to hold the tube completely closed, as in FIG. 11, against the pressures normally occurring within the tube. However, when an excess pressure occurs Within the tube 13g, the latter bulges into the annular groove 32 of the roller 18g, as in FIG. 12, to provide a partial opening through the flattened zone of the tube, thereby permitting some flow of fluid through the flattened zone and relieving the excess pressure. It is apparent that the pressure relief feature of the roller 18g may be used in connection with devices of the described character, whether such devices operate as fluid pumps or as pressure fluid actuated motors.

Referring now to FIG. 14 of the drawings, a device embodying the present invention and generally identified by the reference numeral 10h is there illustrated and constructed to operate as an oscillating fluid pressure actuated motor, for example, for driving the windshield wipers of an automotive vehicle or the like.

As in the previous described embodiments of the invention, the device 10h includes a casing 11h defining a surface 12h against which a flexible, resilient tube 13h is disposed. An assembly 14h is rotatably mounted on the casing 1111 and includes a disc 1512 having a roller 18h mounted thereon adjacent its periphery to locally flatten the tube 13h against the surface 1211. It is apparent that, when a fluid under pressure is admitted to the end 33 of tube 1311 and the opposite end 34 is open to discharge, the roller 18h and the disc 1511 will be driven in the counterclockwise direction, as viewed in FIG. 15, while the admission of pressure fluid at the end 34 and the exhaust or discharge of the fluid at the end 33 will produce clockwise angular displacement of the disc 15h.

In order to cause oscillation of the disc 1512, the ends 33 and 34 of the tube 131: are connected to a two-way valve 35 having an actuating arm 36 extending from the core or valve body thereof and ducts or pipes 37 and 38 communicating with the housing of the valve for respectively supplying fluid pressure to the valve housing and discharging fluid pressure from the valve housing. The two-way valve 35 is constructed so that, with the actuating arm 36 in the position shown in full lines on FIG. 14, the duct 37 communicates with the tube end 34 and the duct 38 communicates with the tube end 33, while displacement of the actuating arm 36 to the position shown in broken lines on FIG. 14 causes the valve 35 to place the duct 37 in communication with the tube end 33 and the duct 38 in communication with the tube end 34.

In order to effect automatic shifting of the arm 36 between the positions shown in full lines and broken lines, respectively, on FIG. 14, the disc 15h has angularly spaced apart lugs 39 and 40 extending therefrom and engageable with the arm 36. Assuming that the arm 36 is in the position shown in full lines to cause clockwise rotation of the disc 15h, it is apparent, that, during such clockwise rotation, the lug 40 will come into engagement with the arm 36 and then shift the latter to the broken line position, where counterclockwise rotation of the disc 15h is effected. During counter-clockwise rotation of the disc 15h, the lug 39 will come into engagement with the arm 36 and then shift the latter back to the position shown in full lines. Hence, the disc 15h will continuously oscillate and can be employed to provide an oscillating drive, for example, for the windshield wipers of an automotive vehicle or the like.

Although various embodiments of the present invention have been described in detail herein and shown in the accompanying drawings, it is to be understood that the invention is not limited to these precise embodiments, and that various changes and modifications may be effected therein without departing from the scope or spirit of the invention, except as defined in the appended claims.

What is claimed is:

1. In a flexible tube fluid pressure device; the combination including rigid casing means defining a backing surface having at least one straight portion, a flexible tube lying against at least said straight portion of the backing surface and having a fabric layer in the walls thereof, said tube being adapted for connection, at one end, to a supply of fluid, and roller means linearly movable along said straight portion of the backing surface and embracing the backing surface and progressively confining said tube in a flattened, fluid-constraining condition between said roller means and said straight portion of the backing surface.

2. In a flexible tube fluid pressure device; the combination including a rigid member defining a backing surface at one side thereof, a flexible tube lying against said backing surface and being adapted for connection, at one end, to a supply of fluid, and roller means movable along said rigid member for progressively confining said tube in a flattened, fluid-constraining condition against said backing surface, said roller means including at least one roller at said one side of the rigid member and exerting radial force against said tube toward the backing surface, separate diametrically opposed stabilizing rollers in rolling contact with said rigid member, and rigid support means connecting the axes of rotation of said one roller and said stabilizing rollers so that the latter react against said rigid member during the action of said one roller on said tube to maintain a predetermined positional relationship between said one roller and said backing surface.

3. In a flexible tube fluid pressure device; the combination including a rigid casing means defining a backing surface, a flexible tube lying against said backing surface and adapted for connection, at one end, to a supply of fluid, roller means movable along said backing surface and pressing against said tube in the direction normal to said surface to progressively flatten said tube between said roller means and backin surface, and separate means movable along said backing surface immediately behind said roller means, considered in the direction of movement of the latter, and exerting a force against the flattened portion of the tube in the transverse direction parallel to said backing surface, thereby to restore the tube to its normal cross-sectional shape.

4. In a flexible tube fluid pressure device; the combination including a rigid casing means defining a backing surface, a flexible tube lying against said backing surface and adapted for connection, at one end, to a supply of fluid, said tube having a fabric layer in the walls thereof, roller means movable along said backing surface and pressing against said tube in the direction normal to said surface to progressively flatten said tube between said roller means and backing surface, and separate means movable along said backing surface immediately behind said roller means, considered in the direction of movement of the latter, and exerting a force against the flattened portion of the tube in the transverse direction parallel to said backing surface, thereby to restore the tube to its normal cross-sectional shape.

5. In a flexible tube fluid pressure device; the combination including a rigid casing means defining a backing surface, a flexible tube lying against said backing surface and adapted for connection, at one end, to a supply of fluid, first roller means movable along said backing and pressing against said tube in the direction normal to said backing surface to progressively flatten said tube between said first roller means and backing surface, and second roller means movable along said backing surface immediately behind said first roller means, considered in the direction of movement of the latter, and pressing laterally against the portion of said tube flattened by the preceding first roller means to restore the flattened portion of the tube to its original cross-sectional shape.

6. In a flexible tube fluid pressure device; the combination including a rigid casing means defining a backing surface, a flexible tube lying against said backing surface and adapted for connection, at one end, to a supply of fluid, and roller means movable along said backing surface with the surface of said roller means acting radially against said tube to progressively flatten the latter between said surface of the roller means and the backing surface of said casing means, at least one of said surfaces of the roller means and casing means having a groove therein into which the flattened portion of said tube can expand to relieve the pressure within the latter.

7. In a flexible tube fluid pressure device; the combination including a rigid casing means defining a backing surface, a flexible tube lying against said backing surface and adapted for connection, at one end, to a supply of fluid, said tube having a fabric layer in the walls thereof, and roller means movable along said backing surface with the surface of said roller means acting radially against said tube to progressively flatten the latter between said surface of the roller means and the backing surface of said casing means, at least one of said surfaces of the roller means and casing means having a groove therein into which the flattened portion of said tube can expand to relieve the pressure within the latter.

8. In a flexible tube fluid pressure device; the combination including a rigid casing means defining a backing surface, a flexible tube lying against said backing surface and adapted for connection, at one end, to a supply of fluid, and roller means movable along said backing surface with the surface of said roller means acting radially against said tube and progressively flattening the latter against said back surface, said surface of the roller means having a peripheral groove intermediate the ends thereof and into which the flattened portion of the tube can expand in response to an excess pressure within the tube, thereby to relieve the excess pressure.

9. In a flexible tube fluid pressure device; the combination including a rigid casing defining an arcuate backing surface, a flexible tube arranged in a plurality of helical turns lying against said backing surface and being adapted for connection, at one end, to a supply of fluid, and a roller movable along said backing surface and acting radially against all of said turns of the tube to progressively flatten each of said turns against said backing surface, said roller having a raised thread on the surface thereof for contact with said tube at the flattened portions of the latter in said turns, said thread having a width which is substantially less than the width of the related flattened portion of said tube so that the folded edges of the flattened portion are free of the flattening force.

10. In a flexible tube fluid pressure device; the combination including a rigid cylindrical casing defining an arcuate backing surface, a flexible tube arranged in a plurality of helical turns lying against said backing surface and being adapted for connection, at one end, to a supply of fluid, and at least one roller movable along said backing surface with the surface of said roller acting radially against all of said turns simultaneously to progressively flatten said turns against said backing surface, one 'of said roller and backing surfaces having a radially raised thread thereon contacting said turns of the tube and having a width less than the width of the tube at the flattened portions of the latter so that the folded edges of each flatened portion are free of the flattening pressure between said roller and backing surfaces.

11. In a flexible tube fluid pressure device; the combination including a rigid casing defining a backing surface; an outer flexible tube lying against said backing surface, an inner flexible tube extending through said outer tube and having a substantially smaller diameter than the latter so that an annular space is defined between said inner and outer tubes with said space and the inner tube being adapted for connection, at one end to supplies of different fluids, and roller means movable along said backing surface and acting radially against said outer tube to progressively compress both said outer and inner tubes between said roller means and said backing surface, thereby to simultaneously pump the different fluids through said inner tube and said annular space, respectively.

12. In a flexible tube fluid pressure device; the combination including a rigid casing defining a backing surface, a flexible tube lying against said surface, roller means, a support carrying said roller means and movable along said surface so that said roller means act radially against said tube to locally confine the latter in a flattened fluid-constraining condition between raid roller means and said backing surface, valve means connected to the opposite ends of said tube, means for supplying a fluid pressure to said valve means, said valve means being operative, in a first position, to communicate one end of said tube with the fluid pressure, and, in a second position, to communicate the other end of said tube with the fluid pressure, and valve actuating means carried by said support and operative to shift said valve means to said first position in response to a predetermined movement of said roller means along said tube toward said one end of the latter and to shift said valve means to said second position in response to a predetermined movement of said roller means along said tube toward said other end of the latter, whereby said roller means is repeatedly moved back and forth along said tube to provide an oscillating movement of said support.

13. In a flexible tube fluid pressure device; the combination including a rigid casing defining a backing surface, a flexible tube lying against said surface, said tube having a fabric layer in the walls thereof, roller means, a support carrying said roller means and movable along said surface so that said roller means act radially against said tube to locally confine the latter in a flattened fluidconst-raining condition between said roller means and said backing surface, valve means connected to the opposite ends of said tube, means for supplying a fiuid pressure to said valve means, said valve means being operative, in a 11 first position, to communicate one end of said tube with fluid pressure, and, in a second position, to communicate the other end of said tube with the fluid pressure, and valve actuating means carried by said support and operative to shift said valve means to said first position in re- I sponse to a predetermined movement of said roller means along said tube toward said one end of the latter and to shift said valve means to said second position in response to a predetermined movement of said roller means along said tube toward said other end of the latter, whereby said roller means is repeatedly moved back and forth along said tube to provide an oscillating movement of said support.

14. In a flexible tube fluid pressure device; the combination including a rigid casing means defining a backing surface, a flexible tube, means connecting one end of said tube to a supply of fluid, roller means movable relative to said backing surface to progressively compress said tube, and support means between said tube and surface, said support means being of less width than said tube when the tube is compressed by said roller so that the edges of said tube can be flexed unrestrictedly toward said support.

15. In a flexible tube fluid pressure device; the combination including a rigid casing means defining a backing surface, a flexible tube, said tube having a layer of fabric in the walls thereof, means connecting one end of said tube to a supply of fluid, roller means movable relative to said backing surface to progressively compress said tube, and support means between said tube and surface, said support means being of less width than said tube when the tube is compressed by said roller so that the edges of said tube can be flexed unrestrictedly toward said support.

16. In a flexible tube fluid pressure device; the combination including a rigid casing means defining a backing surface, a flexible tube lying against said backing surface and having one end connected to a supply of fluid, said tube further having a layer of fabric in the tubular walls thereof and having a support portion of less width than the tubular portion when flattened so that the edges of the flattened tube can flex toward said surface, and roller means movable relative to said backing surface and oper ative to progressively flatten said tube against the backing surface.

17. In a flexible tube fluid pressure device; the combination including a rigid casing defining a backing surface, a flexible tube lying against said backing surface, said tube having a layer of fabric in the walls thereof and, in its uncompressed condition, having a cylindrical outer surface and a generally cylindrical inner surface extending in both directions from a medial plane passing through the center of the tube along the length of the tube, said inner tube surface having indentations at opposite sides thereof in said medial plane, means to maintain a supply of fluid in said tube, and at least one roller movable along said backing surface and operative to progressively flatten said tube against the backing surface to displace the fluid in said tube, said roller having a tube contacting surface with a smaller axial dimension than the width of the tube when the latter is flattened by the roller against said backing surface so that the folded edge portions of the tube are then free of the roller.

References Cited in the file of this patent UNITED STATES PATENTS 314,851 Kelly Mar. 31, 1885 315,667 Serdinko Apr. 14, 1885 320,888 Ruffel June 23, 1885 909,135 Behn Jan. 12, 1909 2,212,733 Grigsby Aug. 27, 1940 2,334,148 Jones Nov. 9, 1943 2,466,618 Stocks Apr. 5, 1949 2,693,766 Seyler Nov. 9, 1954 2,696,173 Jensen Dec. 7, 1954 FOREIGN PATENTS 615,198 Great Britain Jan. 3, 1949 628,785 Great Britain Sept. 5, 1949 

